Coffee's Perks: Studies Find 5 Health Benefits

Besides the caffeine boost and the rich, roasted flavor, coffee has been shown in studies to provide other health benefits, like preventing diabetes and warding off certain cancers.

While drinking two to four cups of coffee a day usually won't have any negative effects, heavy caffeine intake (more than four cups of coffee a day) can cause insomnia, stomach upset, muscle tremors and restlessness, according to the Mayo Clinic. Therefore, health experts say, just because there are health benefits associated with drinking coffee doesn't mean people should change their java-drinking habits so they down several cups a day.

But if you are a regular coffee drinker, there are reasons to be glad.

1. Protects against breast cancer

Women who drink five or more cups of coffee a day are 57 percent less likely to develop estrogen receptor-negative breast cancer than women who drink less than a cup a day, according to a study published this month in the journal Breast Cancer Research.

In this study of 2,818 women with breast cancer and 3,111 women without, researchers found that coffee seemed to protect against only this particular kind of breast cancer, and not estrogen receptor-positive breast cancer or triple negative breast cancer.

2. Wards off stroke

Drinking at least one cup of coffee a day could ward off stroke , according to a study published in March in Stroke: Journal of the American Heart Association.

Swedish researchers analyzed the coffee-drinking habits and health histories of 34,670 women for 10 years, and found that women who drank one or more cups of coffee a day were 25 percent less likely to have a stroke than the women who drank less than a cup of coffee a day.

Even though the finding was in women, researchers said coffee would likely have the same effect for men, too.

3. Reduces risk of diabetes

Having four cups of coffee a day can slash a woman's risk of Type 2 diabetes by 56 percent, according to a study published in January in the journal Diabetes.

In the study of 359 women with diabetes and 359 healthy women, researchers from the University of California, Los Angeles, found that the more coffee the women drank, the less likely they were to have diabetes.

The effect likely has to do with coffee's ability to raise levels of sex hormone-binding globulin (SHBG) in the blood. High blood levels of SHBG are associated with a decreased risk of Type 2 diabetes, according to the study.

4. Improves brain function

Coffee can also improve brain function in mice, according to a 2010 study in the Journal of Alzheimer's Disease.

In that study, researchers gave caffeinated coffee to mice that were engineered to develop Alzheimer's disease. The mice that were given coffee either had the disease progression slow, or the disease never developed at all.

The finding suggests coffee could be a treatment for people with Alzheimer's disease, those researchers said.

5. Reduces prostate cancer risk

Regular coffee intake (either caffeinated or decaffeinated) is associated with a decreased risk of deadly prostate cancer, according to a study published today (May 17) in the Journal of the National Cancer Institute.

In the study of 47,911 men, 5,035 of whom had prostate cancer and 642 of whom had fatal or advanced cases, researchers found that men who drank the most coffee a day (six or more cups) had a nearly 20 percent lower risk of developing prostate cancer than those who drank the least coffee a day.

That association is even higher for lethal prostate cancer the men who drank the most coffee a day had a 60 percent decreased risk of developing the disease, according to the study. And even drinking one to three cups of coffee a day was associated with a 30 percent lower risk of lethal prostate cancer , the study said.

Pass it on: Coffee has many health benefits, including reducing risk of certain cancers and warding off diabetes and stroke.

Amanda Chan was a staff writer for Live Science Health. She holds a bachelor's degree in journalism and mass communication from the Walter Cronkite School of Journalism and Mass Communication at Arizona State University, and a master's degree in journalism from Columbia University.